KR101487018B1 - Eyeglass lens grinding machine - Google Patents

Abstract

assignment

Provided is a spectacle lens processing apparatus capable of appropriately processing a bevel having a good appearance without lengthening a processing time even when the lens curve is a high curve.

Solution

In a spectacle lens processing apparatus for beveling the edge of a lens,

A lens chuck shaft for holding the spectacle lens,

A beveled grinding wheel (a beveled grindstone) includes a V-groove bevel grindstone having a V-groove for simultaneously processing a bevel inclined face on the front side of the lens and a bevel inclined face on the rear side of the lens, Having two bevel grinding wheels, a front bevel grinding wheel and a rear bevel grinding wheel, which process the bevel inclined surfaces of the bevel grinding wheel separately,

And covar position detecting means for detecting the position of the covar on the front surface of the lens and the back surface of the lens based on the lens type data,

And has the following features.

... A mode selecting means for selecting whether the lens is in a low curve lens processing mode or a high curve lens processing mode,

The calculation means - it (calculation means)

And when the low-curve lens processing mode is selected by the mode selecting means, the low-curve lens position determining means determines the position of the bevel apex between the front surface of the lens and the rear surface of the lens by a predetermined arithmetic expression based on the covariance position information by the covarposition detecting means The bevel locus is obtained, and low curve bevel processing data by the V-groove bevel grinding wheel is obtained,

When the high-curve lens processing mode is selected by the mode selecting means, the bevel apex is positioned at a position shifted from the front curve of the lens or from the front curve to the rear side of the predetermined amount based on the covar position information by the covar position detecting means The bevel locus for the high curve is obtained so as to obtain high curve bevel processing data by the rear bevel grinding wheel, the front bevel grinding wheel and the rear bevel grinding wheel,

In the low curve lens processing mode, bevel processing is performed on the edge of the lens by the V-groove bevel grinding wheel based on the low curve bevel processing data, and in the high curve lens processing mode, a rear bevel grinding wheel Or bevel processing control means for performing bevel processing by the front bevel grindstone and the rear bevel grindstone.

Glasses lens processing equipment

Description

[0001] EYEGLASS LENS GRINDING MACHINE [0002]

The present invention relates to a spectacle lens processing apparatus for processing a spectacle lens edge.

In the spectacle lens processing apparatus for processing the edge of the spectacle lens fitted to the spectacle frame, a bevel grindstone having a V-groove for simultaneously processing the bevel inclined face on the front side of the lens and the bevel inclined face on the back side forms a bevel at the lens edge (See, for example, US 6095896 (Japanese Patent Application Laid-Open No. Hei 11-70451)).

In order to suppress a change in size of the bevel which is likely to occur in a grindstone having a V-groove, a front bevel grindstone for machining the bevel inclined face on the front side of the lens and a rear bevel grindstone for beveling the bevel inclined face on the rear side of the lens (See, for example, US Pat. No. 6,089,997 (Japanese Patent Application Laid-Open No. 11-48113), hereinafter referred to as Patent Document 2).

By the way, in recent spectacle frames, frame curves are becoming more severe as the design is diversified. At this time, a lens curve having a high degree of curvature (high curve lens) is used in accordance with the frame curve. By using the apparatus proposed in the above-mentioned Patent Document 2, it is possible to perform the bevel processing in which the bevel slim is suppressed during the bevel processing of the high curve lens. However, also in this apparatus, further improvement is required from the viewpoint of practical use, such as shortening the processing time and forming a bevel having a better appearance.

The object of the present invention is to provide a spectacle lens processing apparatus capable of appropriately processing a bevel having a good appearance without lengthening the processing time even when the lens curve is a high curve.

In order to solve the above problems, the present invention is characterized by having the following configuration.

1. A spectacle lens processing apparatus for beveling the edge of a lens,

A lens chuck shaft for holding the spectacle lens,

A beveled grinding wheel (a beveled grindstone) includes a V-groove bevel grindstone having a V-groove for simultaneously processing a bevel inclined face on the front side of the lens and a bevel inclined face on the rear side of the lens, Having two bevel grinding wheels, a front bevel grinding wheel and a rear bevel grinding wheel, which process the bevel inclined surfaces of the bevel grinding wheel separately,

And covar position detecting means for detecting the position of the covar on the front surface of the lens and the back surface of the lens based on the lens type data,

And has the following features.

... A mode selecting means for selecting whether the lens is in a low curve lens processing mode or a high curve lens processing mode,

The calculation means - it (calculation means)

And when the low-curve lens processing mode is selected by the mode selecting means, the low-curve lens position determining means determines the position of the bevel apex between the front surface of the lens and the rear surface of the lens by a predetermined arithmetic expression based on the covar position information by the covarposition detecting means The bevel locus is obtained, and low curve bevel processing data by the V-groove bevel grinding wheel is obtained,

When the high-curve lens processing mode is selected by the mode selecting means, the bevel apex is positioned at a position shifted from the front curve of the lens or from the front curve to the rear side of the predetermined amount based on the covar position information by the covar position detecting means The bevel locus for the high curve is obtained so as to obtain the high curve bevel processing data by the rear bevel grinding wheel, the front bevel grinding wheel and the rear bevel grinding wheel,

In the low curve lens processing mode, bevel processing is performed on the edge of the lens by the V-groove bevel grinding wheel based on the low curve bevel processing data, and in the high curve lens processing mode, a rear bevel grinding wheel Or bevel processing control means for performing bevel processing by the front bevel grindstone and the rear bevel grindstone.

2. The spectacle lens processing apparatus according to claim 1,

The calculation means calculates the bevel locus for the high curve so that the high curve lens processing mode is selected and the bevel apex is located at a position shifted from the front curve of the lens to a predetermined amount backside, And a bevel locus for the high curve which changes the shift amount with respect to the lens rear surface side according to the thickness of the cornea of the lens is obtained.

3. The spectacle lens processing apparatus according to claim 1,

Wherein when the high curve lens machining mode is selected, the calculation means further calculates a high curve beveling bevel position at which the bevel apex is located on the front curve of the lens when the thickness of the lens barrel obtained by the lens cooper position detecting means is less than a predetermined thickness, And a bevel locus for high curves obtained by shifting the vertex of the bevel along the curve on the front surface of the lens to the backside of the lens when the thickness of the lens corbar is greater than the predetermined thickness.

4. The spectacle lens processing apparatus according to claim 1,

Wherein an angle formed by the beveled inclined surface of the rear bevel grindstone with respect to the axial direction of the lens chuck shaft is larger than an angle formed by the rear beveled inclined surface of the V-

An angle formed by the bevel machining inclined surface of the front bevel grindstone with respect to the axial direction of the lens chuck shaft is smaller than an angle formed by the front bevel machining inclined surface of the V groove bevel grindstone with respect to the axial direction of the lens chuck shaft.

5. The rear bevel grindstone of the spectacle lens processing apparatus of claim 1,

A bevel processing inclined surface on the rear side of the lens and a bevel shoulder processing inclined surface forming a bevel shoulder,

The angle formed by the bevel shoulder machining inclined surface with respect to the axial direction of the lens chuck shaft is smaller than the angle formed by the bevel machining inclined surface with respect to the axial direction of the lens chuck shaft.

6. The spectacle lens processing apparatus according to claim 1,

The rear bevel grindstone has a bevel machining inclined surface on the rear side of the lens and a bevel shoulder machining inclined surface that forms a bevel shoulder. The angle formed by the bevel shoulder machining inclined surface with respect to the axial direction of the lens chuck shaft is determined by the bevel machining inclined surface, Lt; RTI ID = 0.0 >

The calculation means obtains the high curve bevel processing data in which the height of the bevel apex relative to the bevel shoulder when the bevel inclined plane is machined varies depending on the material of the spectacle frame inputted to the frame material input means.

7. The spectacle lens processing apparatus according to claim 6,

The calculation means obtains high curve bevel processing data in which the position of the bevel apex relative to the bevel shoulder is higher than when the material of the spectacle frame is a metal.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the drawings. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic configuration diagram of a processing portion of a spectacle lens edge processing apparatus according to the present invention. Fig.

A carriage unit 100 is mounted on a base 170. The edge of the lens LE held (held) by the lens chuck shafts (lens rotating shafts 102L and 102R) of the carriage 101 is fixed to a grindstone spindle 161a by a coaxial And is processed by pressing. The grindstone group 168 includes a rough grindstone 162 for glass, a grindstone 163 for high-curve bevel finishing having a bevel slope for forming a bevel on a lens of a high curve, A polishing grindstone 164 having a V groove (bevel groove) VG and a flat machined surface, a flat-polishing finishing mirror 165, and a rough grindstone 166 for plastic. The grindstone spindle 161a is rotated by the motor 160. [

The lens chuck shaft 102L is held coaxially with the left arm 101L of the carriage 101 and the lens chuck shaft 102R is rotated with respect to the write arm 101R. The lens chuck shaft 102R is moved toward the lens chuck shaft 102L by the motor 110 mounted on the light arm 101R. Then, the lens LE is held by the two lens shafts 102R and 102L. The two lens shafts 102R and 102L are rotated synchronously by a motor 120 mounted on the left arm 101L via a rotation transmitting mechanism such as a gear. Thereby constituting the lens rotating means.

The carriage 101 is mounted on an X-axis moving support portion 140 which can move along shafts 103 and 104 extending in parallel with lens shafts 102R and 102L and grindstone spindles 161a. A ball screw extending parallel to the shaft 103 (not shown) is attached to the rear portion of the support base 140, and the ball screw is mounted on the rotary shaft of the X-axis movement motor 145. The carriage 101 is linearly moved in the X-axis direction (axial direction of the lens axis) together with the supporting base 140 by the rotation of the motor 145. [ Thereby constituting the X-axis direction moving means. The rotary shaft of the motor 145 is provided with an encoder 146 as a detector for detecting the movement of the carriage 101 in the X-axis direction.

Shafts 156 and 157 extending in the Y-axis direction (direction in which the distance between the axes of the lens shafts 102R and 102L and the abutment spindles 161a vary) are fixed to the support base 140. [ The carriage 101 is mounted on the support base 140 so as to be movable along the shafts 156 and 157 in the Y axis direction. A Y-axis moving motor 150 is fixed to the support base 140. The rotation of the motor 150 is transmitted to a ball screw 155 extending in the Y-axis direction. Then, the carriage 101 is moved in the Y-axis direction by the rotation of the ball screw 155. Thus, the Y-axis direction moving means is constituted. An encoder 158, which is a detector for detecting the movement of the carriage 101 in the Y-axis direction, is provided on the rotating shaft of the motor 150. [

In Fig. 1, the chamfer mechanism part 200 is arranged on the front side of the apparatus main body. Since the well-known chamfer mechanism section 200 is used, its explanation is omitted (for example, see Japanese Unexamined Patent Application Publication No. 2006-239782).

1, a lens position measuring section (lens shape measuring section) 300F, 300R is formed above the carriage 101. [ 2 is a schematic configuration diagram of a measuring unit 300F for measuring the position of the lens coarse on the front surface of the lens. The mounting base 301F is fixed to the supporting base block 300a fixed on the base 170 of Fig. 1 and the slider 303F slides on the rail 302F fixed to the mounting base 301F Respectively. The slide base 310F is fixed to the slider 303F and the measurer arm 304F is fixed to the slide base 310F. An L-shaped hand 305F is fixed to the distal end of the measurer arm 304F and a measurer 306F is fixed to the distal end of the hand 305F. The measurer 306F is brought into contact with the front refracting surface of the lens LE.

A lock 311F is fixed to the lower end of the slide base 310F. The lock 311F meshes with the pinion 312F of the encoder 313F fixed to the mounting support base 301F side. The rotation of the motor 316F is transmitted to the lock 311F through the gear 315F, the idle gear 314F and the pinion 312F and the slide base 310F is moved in the X axis direction. During measurement of the lens cooper position, the motor 316F always keeps the measurer 306F against the lens LE with constant force. The tightening force of the measurer 306F by the motor 316F with respect to the lens refracting surface is given with a light force so that the lens refracting surface is not scratched. As a means for giving a tightening force to the lens refracting surface of the measurer 306F, a known pressure applying means such as a spring may be used. The encoder 313F detects the moving position of the measurer 306F in the X-axis direction by detecting the moving position of the slide base 310F. (Including the lens front position) of the front surface of the lens LE is measured by the information of the movement position, the rotation angle information of the lens shafts 102L and 102R, and the movement information in the Y axis direction.

The configuration of the measurement unit 300R for measuring the position of the back surface of the lens LE is symmetrical with respect to the measurement unit 300F and therefore the configuration of the measurement unit 300F is the same as that of the measurement unit 300F Quot; F " is replaced with " R ", and a description thereof will be omitted.

In the measurement of the position of the lens barber, the measurer 306F is brought into contact with the front face of the lens, and the measurer 306R is brought into contact with the rear face of the lens. In this state, the carriage 101 is moved in the Y-axis direction on the basis of the lens-shaped data, and the lens LE is rotated, so that the positions of the front and back surfaces of the lens for edge processing of the lens are simultaneously measured. Further, in the covar position measuring means configured to move the measurer 306F and the measurer 306R integrally in the X-axis direction, the front surface of the lens and the rear surface of the lens are separately measured. In the above-described lens cooper position measurement unit, the lens chuck axes 102L and 102R are moved in the Y axis direction. However, it is also possible to use a mechanism that relatively moves the measuring person 306F and the measuring person 306R in the Y axis direction have. The position of the lens coarse can be obtained by calculation based on the design data of the lens.

1, a hole machining / groove forming mechanism part 400 is disposed on the rear side of the carriage part 100. As shown in Fig. The structures of the carriage section 100, the lens core position measuring sections 300F and 300R and the hole machining and groove forming mechanism section 400 can basically be those described in US6790124 (Japanese Unexamined Patent Application Publication No. 2003-145328) Therefore, the details are omitted.

The configuration of the X-axis direction moving means and the Y-axis direction moving means in the spectacle lens edge processing apparatus of Fig. 1 is such that the grindstone spindle 161a is relatively moved in the X-axis direction and Y Or may be configured to move in the axial direction. Also in the configuration of the lens cooper position measuring units 300F and 300R, the measurers 306F and 306R may be configured to move in the Y-axis direction with respect to the lens chuck axes 102L and 102R.

Here, the configuration of the grindstone group 168 will be described. Fig. 3 is a view of the grindstone group 168 when viewed in the direction of arrow A in Fig. The width w162 of the glass base grindstone 162 and the width w166 of the plastic base grindstone 166 are all 17 mm. Since the thickness of the corners of a lens is usually 15 mm or less, the width w162 and the width w166 correspond to this and are as narrow as possible.

With respect to the beveling V groove of the finishing grindstone 164 for a low curve, the angle 164 alpha f of the front face machining inclined face with respect to the X axis direction and the angle 164 alpha r of the back face machining inclined face are set such that the frame curve has a gentle lens edge, In order to improve the appearance when fitted in the housing. The depth of the V groove (VG) is less than 1 mm.

The high curve bevel finishing grindstone 163 has a front bevel grinding surface 163F for processing a bevel bevel inclined surface on the front side of the lens LE, And a rear bevel processing inclined surface 163Rk forming a rear bevel processing inclined surface 163Rs to be processed and a bevel shoulder on the rear surface side of the lens. The grindstones of each machining inclined surface are integrally formed in the present apparatus, but may be individual ones.

The angle 163 alpha f of the front bevel machining inclined plane 163F with respect to the X axis direction is gentler than the angle 164 alpha f of the front machining inclined plane of the finishing grindstone 164 and is, for example, 30 degrees. In the case of forming the front bevel on the high curve lens, since the frame curve of the lens (the frame curve of the frame in which the lens is fitted to the frame) is large, in order to improve the appearance on the front side, It is preferable to reduce the angle 163? On the other hand, the angle 163? R of the rear bevel machining inclined plane 163Rs with respect to the X axis direction is larger than the angle 164? R of the back machining inclined plane of the finishing grindstone 164, for example, 45 degrees. In the high-curve frame, it is preferable to increase the angle of the rear bevel (163? R) with respect to the low-curve lens in order to prevent the lens from falling to the rear side and further secure the retention. The angle 163? K of the rear bevel shoulder machining inclined plane 163Rk with respect to the X axis direction is set to be the angle of the rear bevel shoulder machining inclined plane 163Rk of the finishing grindstone 164 Or less, for example, 15 [deg.]. As a result, when attached to the high curve frame, the appearance becomes good and the lens is easily held.

The width w163F of the front bevel machining inclined plane 163F in the X-axis direction is 9 mm and the width w163Rs of the rear bevel machining inclined plane 163Rs is 3.5 mm. As will be described later, in the case of the high-curve lens, since the front bevel inclined face and the rear bevel inclined face are processed separately, they are respectively larger than the low grinding finish grindstone 164 so as not to interfere with each other at the time of processing have. The width (w163Rk) of the rear bevel shoulder machining inclined surface 163Rk is 4.5 mm.

4 is a control block diagram of the spectacle lens edge processing apparatus. A display 5 as a touch panel type display means and input means, a switch 5 as a touch panel type display means and input means, The memory section 51, the carriage section 100, the chamfer mechanism section 200, the lens position measuring sections 300F and 300R, the hole forming / groove forming mechanism section 400, and the like are connected. The input signal to the device can be input by touching the touch pen (or finger) with respect to the display of the display 5. [ The control unit 50 controls the display of the figure and the information of the display 5 by receiving the input signal according to the touch panel function of the display 5. [

In the apparatus having the above structure, the operation of the position measurement of the lens coarse, the rough machining operation on the high curve lens, and the bevel machining operation on the high curve lens will be described.

First, the lens-shaped data rn,? N (n = 1, 2, ..., N) of the frame of the eyeglasses measured by the eyeglass frame shape measuring unit 2 is input by pushing the switch of the switch unit 7 And stored in the memory 51. rn is the diameter, and θn is the data of the longitude. The lens type FT is displayed on the screen 500 of the display 5 and the distance between the center of the frame of the glasses frame (FPD value) and the optical center The layout data such as height can be input. The layout data can be input by operating a predetermined button key displayed on the display 5. [ The processing conditions such as the material of the lens, the type of the frame, the processing mode (bevel processing, flat processing, groove forming processing) and the presence or absence of chamfering can also be set by operating a predetermined button key displayed on the display 5 have. Here, the case where the bevel processing mode is set will be described.

Further, when it is known that the frame curve of the eyeglass frame is large, the high curve mode can be selected by the predetermined button key 501 displayed on the display 5. [ When the advance curve mode is selected, a high-curve bevel finishing wheel (hereinafter, high curve bevel wheel) 163 is set to be used at the time of bevel processing. When the frame curve of the glasses frame is not severe and the finishing wheel 164 is used, the normal machining mode may be selected. When beveling is performed in accordance with the frame of the glasses, which is a high frame curve, the lens LE is selected in advance so as to correspond to the high curve.

When data necessary for machining is input, the lens LE is chucked by the lens chuck shafts 102R and 102L, and the start switch of the switch unit 7 is pressed to operate the apparatus.

The control unit 50 operates the lens shape measuring units 300F and 300R by the start signal to measure the position of the Coba on the front surface of the lens and the back surface of the lens based on the lens type data.

The measurement of the position of the Coba on the front surface of the lens and the rear surface of the lens will be described with reference to Figs. 5A to 5B and Figs. 6A to 6B. 5A shows the lens shape FT and the geometric center FC. (N = 1, 2, ..., N) with respect to the geometrical center FC is also shown. As shown in Fig. 5A, the radial angle? n on the right side in the drawing is set to 0 deg. with respect to the geometrical center FC, theta] n is increased. Fig. 5B is a graph showing changes in the length of the longitude rn with respect to the long-axis angle? N.

6A is a view showing the lens cores when the lens LE is processed into the lens shape FT in the direction of the corner C1. 6B is a graph of the covariance position fxn of the lens front side refracting surface and the covar position rxn of the lens rear side refracting surface with respect to the lens type (FT) Respectively.

When the position of the covar of the lens LE is measured on the basis of the lens shape FT, the control unit 50 rotates the lens shafts 102R and 102L so that the diameter difference? N (in this case, The measuring device 306F and the measuring device 306F which move the lens shafts 102R and 102L in the Y-axis direction and come into contact with the entire surface of the lens, on the basis of the large-diameter length rn of each lens And controls the position in the Y-axis direction of the measurer 306R to be brought into contact with the rear surface of the lens. During the measurement, the observers 306F and 306R are tightened by the motors 316F and 316R, respectively, with a light force on the lens refracting surface. The covariance positions fxn and rxn are obtained by the encoders 313F and 313R, respectively.

Next, a case of rotating the lens chuck shafts 102R, 102L at a constant angular speed will be described. By increasing the rotation speed of the lens shafts 102R and 102L, the measurement time can be shortened. However, in the vicinities of the corners C1 to C4, which are the inflection points at which the diameter length rn of the lens mold FT is abruptly changed, the positions of the measurers 306F and 306R in the Y- Along with this, the covariance positions fxn and rxn also change abruptly near the corners C1 to C4. Particularly, in the corners C1 to C4, the longitude rn and the covariance positions fxn and rxn are changed from increase to decrease. At this time, if the rotational speed of the lens is too fast, the followability of the observers 306F and 306R in the X-axis direction is deteriorated with respect to the refracting surface of the lens LE due to the effect of inertia or the like. The trackability after the change of the diameter length rn from the increase to the decrease in the radius C1 at the corner C1 is deteriorated and the measurement accuracy is deteriorated with respect to the measurer 306R for measuring the position of the covar on the rear surface of the lens. The position of the covar is suddenly changed along with the abrupt change in the length of the lens Rn in the vicinity of the corner C1 with respect to the measurer 306F for measuring the position of the covar on the front face of the lens, . Further, the more the lens curve is, the larger the tendency becomes.

In the portion where the change in the diameter length rn is large and the change in the diameter length rn from increase to decrease occurs, the abrupt movement control of the lens shafts 102L, 102R in the Y- , And 306R may deviate from the locus of the lens shape FT.

On the other hand, if the rotation speed of the lens is made sufficiently slow so as to ensure the measurement accuracy at the corners (C1 to C4) at which the diameter (rn) changes abruptly by rotating the lens LE at a constant speed, The time is longer. Particularly, in the case of bevel machining, for example, since the position of the covar is measured at two points of the bevel apex position and the bevel bottom, the longer the machining time is, the longer the machining time becomes.

Here, in the portion of the lens mold FT remote from the corners C1 to C4 (in the vicinity of 0 DEG, 90 DEG, 180 DEG, and 270 DEG in Figs. 5A to 5B) And the change amount of the position of the covar is also small, it is possible to ensure the followability of the measurers 306F and 306R with respect to the lens refracting surface, even if the speed of the lens rotation is fast for this portion.

Thus, in order to shorten the measurement time while securing the measurement accuracy, the rotation speed (the rotation speed of the lens) of the lens shafts 102R, 102L is changed in accordance with the change in the length of the lens rn. That is, at a portion where the change in the length (rn) is large, the rotation speed of the lens is made slow to secure the measurement accuracy. On the other hand, in the portion where the change amount of the longitude rn is small, the rotation speed of the lens is increased in order to shorten the measurement time.

Hereinafter, a preferred example of the lens rotation speed control will be described using Figs. 7A to 7C. The control unit 50 carries out a differential calculation on the longitude rn of the lens-shaped data rn,? N of the spectacle frame of Fig. 5A with respect to the longitude? N. When the measurement point of the position of the covar around one circumference of the lens type is set to 1000 points, the tolerance angle? N changes every 0.36 °. The graph of Fig. 7A shows the relationship of the result of differential calculation (hereinafter referred to as differential value rdn) at the longest angle? N. Next, the control unit 50 calculates the absolute value of the obtained derivative value rdn. Fig. 7B shows the relationship between the absolute value Ardn in the longitude angle [theta] n obtained as a result of the calculation of the absolute value. The value of the absolute value Ardn is large at the four corners C1 to C4 of the lens type FT.

The control unit 50 switches the angular velocity for rotating the chuck shafts 102R and 102L in accordance with the absolute value Ardn. The conversion of the angular velocity will be described. 7C, the control unit 50 obtains the rotational angular velocity V? N that is almost in inverse proportion to the absolute value Ardn at the greatest angular difference? N, and calculates the rotational angular velocity V? 102R, 102L. That is, the chuck shafts 102R and 102L are rapidly rotated in the portion where the rate of change of the diameter length rn is small, and the chuck shafts 102R and 102L are rotated slowly as the rate of change of the diameter length rn increases. The angular velocity V? N is set such that the measurer 306F or 306R follows the refracting surface even in the portion where the absolute value Ardn, which is the rate of change of the length (rn) Can be determined by experiment.

By thus rotating the chuck shafts 102R and 102L at the rotational angular velocity V? N corresponding to the rate of change of the longitude rn, the measurers 306F and 306R per unit time move in the Y- Can be made almost constant. Thus, the measurement time can be shortened while securing the measurement accuracy, and the position of the covar on the refracting surface of the lens LE can be measured.

The case where the refractive surface of the lens LE is measured by the rotational angular velocity V? N in inverse proportion to the absolute value Ardn has been described above. However, the calculation of the rotational angular velocity V? N in accordance with the change in the diameter length rn is not limited to this. For example, the rotational angular velocity V? N in FIG. 7C is stepwise changed so that the rotational angular velocity is divided into two levels, for example, the rotational angular velocity V? C and the high rotational speed V? Or may be configured to switch. In addition, the switching step is not limited to the two steps, but may be three or more steps.

In the above description, the rotational angular velocity V? N is changed on the basis of the rate of change in the length of the lens type FT. However, even when the rotational angular velocity V? N is changed in consideration of the change in the X- do. In the case of the same lens type (FT), when the power of the lens LE is high, for example, when the curve on the back surface is urged by a negative lens, or when the lens is a high curve lens, The change in the X-axis direction becomes large. It is predicted that the change becomes large even after the change in the detection result is observed in at least one of the measurer 306F or 306R as the measurement result by the measurers 306F and 306R in the measurement process of the covariance position, The control unit 50 controls the rotational angular velocity to be slow. When the changes in the detection results of the measurers 306F and 306R are small then the measurers 306F and 306R tend to follow the lens LE so that the controller 50 controls the angular velocity of rotation to be fast.

When a lens curve or a frame curve of a frame of glasses is input instead of using the change of the position of the covar in the X axis direction obtained in the measurement process, It is possible to roughly calculate the change in the position of the Coba. Therefore, the rotational angular velocity may be controlled based on the calculation result. It is more preferable that the control is based on both.

In the present embodiment, the lens LE is sandwiched from the lens chuck shafts 102R and 102L so as to be directed to the substantially vertical direction with respect to the mounting surface on which the main body 1 of the processing apparatus is installed. Then, the refracting surface of the lens LE is measured by the measurers 306F and 306R located in the parallel direction with respect to the mounting surface. However, the control of the rotational angular velocity is not limited to these positional relationships.

For example, when the refracting surface of the lens is sandwiched so as to face in an almost parallel direction with respect to the mounting surface of the main body of the processing apparatus, and the measuring surface of the lens is abutted from the substantially vertical direction with respect to the mounting surface , And US6099383 (Japanese Unexamined Patent Publication No. Hei 10-225855)), the above-described control of the rotational angular velocity can be applied.

Next, the operation after measuring the position of the covar will be described. Further, in the case of the bevel processing mode, the covariance position measurement is performed at two points, for example, at a position between a bevel apex in the same meridian direction and a bevel bottom (a position where the bevel shoulder and the bevel inclined face intersect). When the position of the Cova on the front surface of the lens and the back surface of the lens are obtained, the control unit 50 carries out a bevel calculation for obtaining bevel locus data formed on the lens LE based on the lens type data and the Cova position information according to a predetermined program . An operation for obtaining the bevel locus data will be described later.

If the bevel calculation can be performed, a simulation screen capable of changing the bevel shape is displayed on the display 5 (see Fig. 8). On the simulation screen, a bevel curve value Crv by bevel calculation is displayed on the display unit 511. [ In the simulation screen, the bevel curve value can be changed. In addition, the amount of parallel movement of the bevel apex position to the lens front surface side or the rear surface side can be input into the input box 512. A lens shape FT and a bevel cross sectional shape 520 are displayed on the screen. By designating the position of the cursor 530 on the lens shape FT by the button key 513 or 514, the bevel cross section 520 is changed to the designated position state.

When the machining start switch of the switch unit 7 is pressed after the bevel simulation screen is displayed, the control unit 50 controls the motors 145 and 150 that move the carriage 101 according to the machining sequence, Based on the processing data, the edge of the lens LE is rough machined by the plastic grindstone 166. The coarse machining locus of coarse machining data is calculated as a locus leaving a predetermined finishing value in the lens-shaped data.

Here, in the processing of the plastic lens according to the present embodiment, processing is performed so that the edge of the lens LE does not protrude out of the grinding wheel width of the grinding wheel 166 (hereinafter, ).

The effective utilization of the grinding wheel width will be described. 9 and 10A to 10B show the positional relationship between the lens LE of the high curve chucked by the lens shafts 102R and 102L and the grindstone group 168 in the direction of arrow A in Fig. Fig. The hatched portion on the lens LE represents a cross section of the lens shape (FTr) of the lens to be rough-machined.

First, prior to describing the effective use of the grinding wheel width, the conventional rough machining control will be briefly described. The control unit 50 controls the lens side end 1030 of the lens chuck shaft 102L to move away from the left boundary 166a of the grindstone 166 by a predetermined distance (for example, 2 mm The carriage 101 is moved in the X-axis direction by driving the motor 145 so that the carriage 101 is positioned at the inner position 166p. Thereafter, the motor 150 is driven to change the distance between the axes of the lens shafts 102R, 102L and the grindstone spindle 161a according to the lens type FTr, and the edge of the lens LE is moved to the grindstone 166, . At this time, in the rough high curve lens LE, the outermost periphery LEO of the lens LE emerges outward from the right boundary 166b of the grindstone 166. [ If the coarse machining is continued in this state, another area of the lens LE is rough machined while the outer periphery LEO is left. When the peripheral portion LEO is removed from the lens LE as processing progresses, the lens LE may be cracked.

It is also assumed that the arrangement order of the grindstone 166 and the other grindstone is changed and that the finishing grindstone 164 is disposed on the right side of the grindstone 166 (on the rear side of the lens). In this case, the outer peripheral portion LEO of the grindstone 166, which has been evacuated from the right boundary 166b, is caught by the grindstone 164 and is pressed against the grindstone 164 to increase the load on the lens LE, The axis angle of the actual lens LE deviates from the rotation angle of the lens units 102R, 102L. It is also a factor that causes deformation of the lens LE or lens cracking. The above problem can be solved by making the width of the high grinding wheel 166 sufficiently large corresponding to the processing of the high curve lens. In addition to the grinding wheel 166 and the finishing grindstone 164 for plastic, A plurality of grindstones such as a glass grindstone 162 and a high-curve bevel finishing grindstone 163 are mounted coaxially to increase the overall grindstone width. Therefore, if the width of the rough grindstones 166 and 162 is increased, the lens shafts 102L and 102R must be configured so that the entire grindstone width can be moved, thereby increasing the size of the apparatus.

Thus, the control unit 50 calculates the position of the front and / or rear surface of the lens in the X-axis direction based on the front curve of the lens and / or the back curve and the movement information in the Y-axis direction, The roughing control is performed so that the corner of the lens LE is accommodated within the width of the grindstone 166. [ 10A to 10B are views for explaining a first working method of effective use of the grinding wheel width.

First, the controller 50 obtains the radius CRf of the lens front curved line by substituting any four points from the Covari position of the front face of the lens measured by the lens shape measuring units 300F and 300R into the equation of the sphere The front curve is automatically input to the control unit 50). The input of the curve data on the front surface of the lens may be a configuration in which the front curve of the lens LE is known in advance (obtained by measuring with a well-known curve system), and the input is inputted through the input screen of the display 5.

Here, in FIG. 10A, the curve circle of the radius CRf is defined as LECf. It is assumed that the center of the curve circle LECf is on the rotation center 102T of the lens chuck shafts 102R and 102L. The moving distance of the lens side end 1030 with respect to the origin xo of the lens shafts 102L in the X axis direction is xt (movement information in the X axis direction). Let Ly be the distance in the Y axis direction from the rotation center 102T to the turret wheel 166 and LEC1 be the point on the curve circle LECf separated by the distance Ly from the rotation center 102T. The distance in the X axis direction from the point LEC1 on the curve circle LECf to the lens side end 1030 is defined as? Xf. The distance DELTA xf is determined by the radius CRf and the distance Ly of the curve circle LECf on the front surface of the lens. The control unit 50 sets the origin Xo so that the point LEC1 on the curve circle LECf corresponding to the distance Ly in the Y axis direction is always located at the position 166p on the grindstone 166. [ The distance xt is calculated by the position 166p and the distance? Xf.

The controller 50 controls the movement of the lens LE in the Y axis direction based on the lens shape FTr and also controls the movement of the lens LE based on the distance xt corresponding to the distance Ly LE) in the X-axis direction. At this time, the lens side end 1030 is moved to the movement trajectory along the curve circle LECf in front of the lens. Thereby, the lens LE is moved so that the front surface of the lens is always at the position 166p. The front surface of the lens LE does not come out from the left end boundary 166a of the right grindstone 166 and the width of the right grindstone 166 is wider than the cove of the lens LE, Is not projected from the right boundary 166b of the horizontal grindstone 166 and the corners of the lens LE are formed.

If the curve circle LECf in which the lens front surface is located always comes to the predetermined position 166p on the grinding wheel 166, even if the high curve lens is used, the lens rear position can be adjusted so as not to come out from the width of the grinding wheel 166 Processing can be performed. Even if the width w166 of the ground stone 166 is narrowed, the width of the grinding wheel 166 can be utilized effectively.

In the coarse machining control, the front side of the lens is used as a reference. In the same accident, as shown in Fig. 10B, coarse machining control based on the lens rear side may be used. In this case, the control unit 50 obtains the curve circle LECr from the rear curve radius CRr of the lens LE. The point LEC2 on the curve circle LECr corresponding to the distance Ly in the Y axis direction is moved to a predetermined position (for example, 2 mm) set at a predetermined distance (2 mm) from the right end face 166b of the rough wheel 166 The distance xt is calculated by the position 166q and the distance DELTA xr with respect to the origin point xo so as to be positioned at the predetermined position on the rear side of the lens 166q. The control unit 50 controls the movement of the lens LE in the Y-axis direction and the movement in the X-axis direction based on the calculation result. The back curve radius CRr is obtained from the position measurement of the back of the lens and input to the control unit 50. The result of measuring the back curve of the lens may be input in advance.

The data of both the front curve radius CRf and the rear curve radius CRr are inputted and the movement of the lens LE in the Y axis direction is controlled so as to be accommodated in the width of the grindstone 166 The movement information in the X-axis direction may be obtained. In this case, for example, a curve circle corresponding to the middle between the front curve radius (CRf) and the rear curve radius (CRr) is obtained, and the curve circle corresponding to the middle The information is computed to perform coarse processing. When the distance between the curve sources LECf and LECr in the X axis direction becomes shorter than the width of the grindstone 166, the point at which the curve circle LECf on the front surface of the lens contacts the grindstone 166 is the position 166p And the movement information in the X-axis direction is determined in a range in which the point where the curve circle LECr of the lens back surface contacts the table wheel 166 is located inside the position 166q.

The curvature circle LECf on the front surface of the lens and the curved circle LECr on the rear surface of the lens are both set to the width (position 166p) of the roughing grindstone 166, It is preferable to control the movement of the X axis such that the surface of the lens 166 is roughly processed so that the Kovar of the lens LE appropriately covers the surface of the lens 166q.

Further, the problem of rough working only on the Y-axis movement is more likely to occur as the lens LE has a higher curve. Therefore, in the case where the curvature of the lens LE is not so high by using the effective use of the above-mentioned grinding wheel width effective when the lens LE is a high curve (for example, the lens curve is 6 or more) It is also possible to adopt a constitution in which rough machining is performed only by controlling the Y-axis movement. However, in order to make the machining apparatus main body 1 more compact without increasing the width of the grindstone 166, the grindstone width effective use processing described above is used even if the lens LE is not a high curve .

10A to 10B can be applied even when the outer diameter of the lens LE is not known before processing. However, it is also possible to move the lens LE in the Y-axis direction and the X-axis direction at the same time There is a possibility that the load applied to the lens LE slightly increases in comparison with the movement in the Y-axis direction only. In order to reduce this, a second working method of effective use of the grinding wheel width in which the lens LE is moved in the X-axis direction only when the corner of the lens LE is projected out of the width to the grinding wheel 166 is described below Explain.

First, in order to know the thickness of the cove of the lens before machining, the outer diameter of the lens LE before machining (dough lens) is obtained as follows. 11A to 11B, the control unit 50 drives the motor 145 so that the lens side end 1030 is positioned at the position 166p of the grindstone 166, (102L) in the X-axis direction. 12, the control unit 50 determines whether or not the geometrical center FC of the lens type, the optical center Eo of the lens LE, and the center 166T of the grindstone 166 are on the same straight line The lens 120 is driven by the motor 120 to rotate the lens. Further, when the optical center Eo of the lens LE is an optical center chuck coinciding with the rotation center 102T, the geometric center FC need not be specially considered. The control unit 50 moves the lens chuck axes 102L and 102R in the Y axis direction by driving the motor 150 without rotating the lens LE so as to move the lens LE to the grindstone 166 Let's face it. At this time, the control unit 50 compares the drive pulse signal of the motor 150 with the pulse signal output from the encoder 158, and when the deviation occurs, the lens LE is moved to the grindstone 166 It is detected that the contact state is reached. The reason for this is that the amount of movement of the lens LE converted from the drive signal of the motor 150 due to the reaction force received from the grindstone 166 when the lens LE comes into contact with the grindstone 166, (LE) is reduced.

When the lens LE comes into abutment against the grindstone 166, the grindstone 166 is moved in the direction of rotation of the motor 160 due to the reaction force of the grindstone 166 from the lens LE, It is possible to detect that the lens LE comes into contact with the grindstone 166. In this case, Similarly, it can be detected that the lens LE abuts against the grindstone 166 from a change in the driving current of the motor 150 for Y-axis movement. By using both the displacement in the Y axis direction and the change in the amount of current of the motor 160, the reliability of detection that the lens LE comes into contact with the grindstone 166 is improved.

At this time, although the outer periphery of the lens LE may come out from the grindstone 166 at this time, since it is a sufficiently short time, the influence of the shaft misalignment or the like can be ignored.

The control unit 50 obtains the Y axis position of the rotation center 102T at this time from the encoder 158 and determines the radius Rc of the grindstone 166 ) Of the lens LE and the layout data (distance r10) of the optical center Eo with respect to the geometric center FC can be calculated.

11A, the control unit 50 previously calculates the curve circle LECf on the front surface of the lens and the curve circle LECr on the rear surface of the lens based on the input of the curve data. The control unit 50 obtains the distance Ly from the radius rLE of the lens LE to the outer circumference of the lens 102T. This distance Ly and the curve circle LECr on the rear surface of the lens allow the distance from the lens side end 1030 to the back surface of the lens (curve circle LECr) when the lens LE comes into contact with the grindstone 166 And the distance DELTA xr to the point LEC4 is obtained. It is possible to determine whether the covar point LEC4 on the rear surface of the lens is projecting outward from the predetermined position 166q on the back surface side of the lens of the primary grindstone 166. At the same time, 166q to the point LEC4 can also be calculated.

At this time, if the lens back surface (claw LEC4) is not projected out of the predetermined position 166q of the grindstone 166, the lens LE is rotated while Y The coarse machining is performed by the movement control only in the axial direction. When the lens back surface (claw LEC4) is projected out of the predetermined position 166q of the grindstone 166, the lens chuck shaft 102L is moved to the left side (lens front side) Processing is started (see Fig. 11B).

The control unit 50 calculates the distance (? Xf) from the lens side end 1030 to the front surface (curve circle LECf) of the lens in accordance with the distance Ly (movement information in the Y axis direction) do. The controller 50 reduces the distance Ly in the Y-axis direction by the progress of the rough machining so that the lens front face of the curve circle LECf and the predetermined position 166p of the front face of the lens 166, Is obtained by? Xf. Then, the lens LE is moved to the rear side before the front surface of the lens is detached from the predetermined position 166p of the grindstone 166 to the outside. The movement position is set so that the rear surface of the lens, which is obtained from the curve circle LECr, does not protrude from the predetermined position 166q of the grindstone 166. [ If the lens front end position LEC3 of the curve circle LECf obtained from the lens side end 1030 or the machining lens mold can be moved to the position 166p of the grindstone 166, It is possible to perform the coarse processing.

With the above-described rough machining control, it is possible to effectively use the grindstone width of the small grindstone 166 even in the case of the high-curve lens, and to perform the grind machining so that the lens does not come out from the grindstone 166 . 11A to 11B, it is possible to reduce the movement in the X-axis direction during the rough working, so that the extra load applied to the lens LE during the projection can be reduced.

As the means for obtaining the outer diameter of the lens LE before machining, the lens core position measuring units 300F and 300R may be used. The control unit 50 sets the linear direction 180 connecting the optical center Eo and the geometric center FC (rotation center 102T) to the Y axis direction by rotating the lens , At least one of the examinee (306F or 300R) of the lens shape measuring unit (300F) is brought into contact with the lens mold (FT). Thereafter, the Y axis movement of the lens LE is controlled so that the measurer 306F or 306R moves along the straight line 180 in the outward direction of the lens shape FT. If the measurer 306F or 306R deviates from the state of being in contact with the refracting surface of the lens LE, the detection information of the position of the covar of the encoder 313F or 313R abruptly changes. By obtaining the movement position in the Y-axis direction at this time from the encoder 158, it is possible to calculate the radius rLE which is the outer diameter before the lens LE is machined. If the outside diameter before the lens LE is known in advance, the operator may input the radius rLE on the predetermined input screen of the display 5. [ The measurer 306F or 306R may be moved along the linear direction 182 opposite to the linear direction 180 with respect to the optical center Eo.

As described above, the effective use of the grinding wheel width has been described, but the processing is not limited to the above. The relative movement of the grindstone and the lens is controlled based on the refracting surface information of the lens (curve data of at least one of the front surface or the back surface of the lens) so that the lens is not projected out of the grindstone when the grindstone is processed with the predetermined grindstone , It is included in the technical idea of effective utilization of the grinding wheel width.

Next, a bevel finishing process after rough working will be described. As described above, in the bevel processing mode, the high curve mode and the low-curve mode, which is the normal processing mode, can be selected by the button key 501 of the display 5 in accordance with the curve of the lens fitted in the spectacle frame have.

When the low curve mode is selected, bevel processing is performed by the finishing grindstone 164 having a V-groove, and bevel locus data is calculated by the control unit 50. [ The bevel locus data is calculated by a predetermined arithmetic expression so that the bevel apex is located between the front surface of the lens and the rear surface of the lens, based on the covar position data and the lens type data on the front and rear surfaces of the lens by the lens position measurement. For example, in addition to being computed as a trajectory in which the bevel apex is disposed on the entire circumference of the entire diameter to divide the thickness of the corners into a predetermined ratio (3: 7 or the like), a trajectory shifted to the back side of the lens by a bevel curve along the front curve of the lens . The bevel locus data may be computed as described in JP-A-2-212059. The beveling process by the finishing grindstone 164 having a V-groove is described in JP-A-2-212059 and the like, and is not described here.

Next, the calculation of the bevel locus data in the case of the high curve mode (high curve lens) will be described. In the case of the high curve mode, the bevel apex locus is basically calculated to follow the lens front curve. In order to improve the appearance, bevel formation when fitted in the high curve frame (MFR) is carried out in such a manner that the thickness of the corners of the lens is not more than a predetermined value t0 (for example, 3 mm) The bevel apex VTP is located on the lens front curve and is set to form a bevel slope VSr only on the lens back side. This is because the lens sandwiched by the high curve frame MFR is used as a high curve lens (a lens having a large curvature on the front surface of the lens) aligned with the frame curve so that the entire lens surface can serve as a front bevel inclined surface, Further, if the front bevel inclined face having a different angle from the front face of the lens is formed to be large, the boundary line of the two generated due to the difference in angle is conspicuous and the appearance is deteriorated. Further, when the thickness of the core is thicker than the predetermined value t0, the bevel apex VTP is set to be shifted toward the rear surface of the lens depending on the thickness of the core. Further, a small surface may be formed as a kind of chamfer by the front bevel processing grindstone on the lens front side, and in this case, the bevel apex moves to the rear side.

Let the bevel vertex locus data be (rn,? N, Hn) (n = 1, 2, ..., N). rn is the length of the lens-shaped data, and? n is the diameter of the lens-shaped data. Hn is set by directly applying the Covar position data of the lens front face detected by the lens cooper position measuring unit 300F as it is in the setting of forming the bevel inclined face VSr on the back side of the lens as the position data in the X axis direction .

Next, a method of obtaining the rear bevel machining data for forming the bevel inclined surface VSr on the rear surface side of the lens by the rear bevel machining inclined surface 163Rs based on the bevel vertex locus data rn,? N, .

15A, the bevel height vh (the distance in the Y-axis direction from the bevel bottom Vbr to the bevel apex VTP at which the bevel inclined face VSr and the bevel shoulder intersect) is set in advance. The setting of the bevel height vh can be arbitrarily set by the display 5 in addition to the use in which the control unit 50 calls in advance what is stored in the memory 51. [ The control unit 50 obtains a machining point for securing the bevel bottom Vbr having the set bevel height vh as follows.

Let Rt be the radius of the grindstone of the intersection 163G on the grindstone 163 that abuts the bevel bottom Vbr. Dimensional lens data rn,? N of bevel vertex locus data (rn,? N, Hn) (n = 1, 2, 3, ..., N) Axis distance LV (the distance between the lens rotation center 102T and the center of rotation of the grinding wheel)

. Then, the same calculations as in the formula (1) are carried out by rotating the lens-shaped data rn,? N around a lens rotation center by an arbitrary small angle. The rotation angles at this time are calculated over the entire circumference with? I (i = 1, 2, 3, ..., N). By obtaining the maximum value LVi of each LV in each? I, reference machining data LVi,? I of the machining point for securing the bevel bottom (Vbr) can be obtained for each lens rotation angle? I.

Next, a machining point in the X-axis direction is determined so that the bevel apex is in contact with the rear bevel machining inclined surface 163Rs in association with the reference machining data LVi,? I. Here, for the sake of convenience, the bevel vertex locus data (rn,? N, Hn) can be obtained by assuming an orthogonal coordinate system having the lens shafts 102R,

(Xn, yn, zn). At this time, the grinding surface of the rear bevel machining inclined surface 163Rs which makes the orthogonal coordinate system equal to the origin is represented by the following expression.

(X, Y, Z) in the equation (3) becomes a virtual conic vertex coordinate constituting the abrasive surface of the rear bevel machining inclined plane 163Rs, and Z on the side of the rear bevel machining inclined plane 163Rs,

. Further, when the above-mentioned machining reference trajectory is converted into orthogonal coordinates with? I being? N,

. This and the bevel vertex locus data (xn, yn, zn) are substituted into equation (2) to obtain the maximum value Zmax of Z. [ The same calculation is performed over the entire circumference while rotating the center of the lens rotation about an arbitrary angle ξi (i = 1, 2, 3, ..., N) of the bevel vertex locus data (xn, yn, zn) By obtaining the maximum value (Zmax i) of Z at? I in each case, a machining point in the lens axial direction in which the bevel apex contacts the rear bevel machining inclined plane 163Rs is obtained. (LVi, Zmaxi,? I) (i = 1, 2, 3, ..., N) become the rear bevel machining data by this and the reference machining data LVi,

The control unit 50 controls the Y axis movement of the carriage 101 on the basis of the data LVi for each lens rotation angle xi of the rear bevel processing data and controls the X axis movement of the carriage 101 Is controlled based on the data Zmax i. Thereby, the bevel inclined surface VSr is formed only on the lens rear surface side. Since the bevel inclined surfaces on the front surface side of the lens are not simultaneously processed but only the bevel inclined surfaces on the rear surface side of the lens are individually processed, the problem of bevel slippage due to interference can be reduced even in the case of high curve bevels. Before the bevel processing by the rear bevel machining inclined surface 163Rs or after the machining, the bevel processing is performed so that a bevel It is preferable to control the apex portion to be flat-finished.

Even in the case of the high-curve lens, it is preferable to form the bevel shoulder by the processing inclined surface 163Rk on the rear side of the lens. The reason for this will be described with reference to Fig. The bevel shoulder 163Rk formed on the rear surface of the lens LE may have a curved shape when the angle formed by the rear bevel shoulder machining inclined surface 163Rk of the grindstone 16 with respect to the reference line 1610 is 0 DEG when the lens LE is a high curve, And is formed in a direction parallel to the reference line 1610, such as a dotted line 1632. [ In this case, since the frame (MFR) interferes with the dotted line 1632 indicating the bevel shoulder, the fitting property to the frame MFR is not preferable. Conversely, the rear bevel shoulder machining inclined surface 163Rk is not formed on the grindstone 163 and the inclination of the rear bevel machining inclined surface 163Rs is uniformly distributed from the bevel apex VTP of the lens LE to the rear surface of the lens LE When the bevel inclined surface is formed at an angle, the inclined surface is formed to be represented by a dotted line 1634, and a bevel shoulder is not formed (only the bevel inclined surface is formed from the bevel apex VTP to the rear surface of the lens LE). At this time, when the lens LE is inserted into the frame MFR in the direction of the arrow 1636, a gap d1634 between the corner of the rear surface of the lens LE and the frame MFR is formed to be large, Appearance is undesirable. Therefore, when the bevel inclined surface is formed on the rear surface side of the lens LE of the high curve, an angle formed by the rear bevel processing inclined surface 163Rs and the reference line 1610 with respect to the reference line 1610 It is preferable to form the inclined surface 163Rk which forms the bevel shoulder at a smaller angle.

Further, in the case of the lens LE of high curvature, the front surface of the lens is prevented from being sufficiently engaged with the front surface 1640 of the groove of the frame MFR without forming a bevel on the front surface side of the lens by the front bevel processing inclined surface 163F In the state of being fitted. Therefore, if the thickness of the lens LE measured by the lens-core position measuring units 300F and 300R is small, a bevel on the front surface of the lens is not required. Therefore, even in the case of the high-curve lens, it is possible to perform the beveling process with a good appearance without lengthening the processing time for the normal bevel processing time by the finishing grindstone 164.

However, in the case where the thickness of the corners of the lens LE is large (for example, 3 mm or more), it is preferable to form a bevel inclined surface on the front surface of the lens. Fig. 16A shows a case in which the lens is thicker in thickness and sandwiched in the frame MFR without forming a bevel on the lens front surface side. When the lens LE is sandwiched by the frame MFR, the lens LE is projected out from the rear side of the frame MFR so that the appearance of the lens LE when viewed from the side is not preferable.

On the other hand, in FIG. 16B, a bevel inclined surface VSf is formed on the front surface of the lens by the front bevel processing inclined surface 163F with respect to the same lens LE as in FIG. 16A, Fig. 16B shows a case in which it is sandwiched. As shown in Fig. 16A, the lens LE does not protrude from the frame MFR but fits on the rim with a good appearance when viewed from the side.

In view of the safety of the wearer of the eyeglasses, it is not preferable that the lens LE be pulled out in the direction of the arrow 1650 (rear side) with respect to the frame MFR (see Fig. 14). That is, the rear bevel machining inclined surface 163Rs with respect to the reference line 1610 is secured to the frame MFR more than the front bevel formed by the front bevel machining inclined surface 163F , The inclination angle is made large. The smaller the beveled portion d1642 that is not covered by the frame MFR among the front side bevel inclined faces VSf is preferable in terms of appearance (the front bevel machining inclined face 163F with respect to the base line 1610) If the angle formed is larger than necessary, it is not preferable from the viewpoint of appearance). In the present embodiment, the front bevel machining inclined surface 163F is inclined at an angle of 30 degrees with respect to the reference line 1610, and also at 45 degrees with respect to the reference line 1610 of the bevel machining inclined surface 163Rs In the direction of angle. However, these angles are not limited to the above.

A case in which a bevel inclined surface is formed on the entire surface of the lens will be described (see Fig. 15B). When the thickest portion (hereinafter referred to as the rear portion) of the covar thickness measured by the covariance position measuring units 300F and 300R is equal to or larger than a predetermined value t0 (3 mm), the control unit 50 controls the bevel inclination . At this time, when the final portion is less than 3 mm and less than 4 mm, the control unit 50 calculates the bevel apex locus so that the distance d192 from the front side of the lens LE to the bevel apex VTP is 0.3 mm . The distance d192 is set to 0.4 mm when the last portion is less than 4 mm and less than 5 mm, and the distance d192 is set to 0.5 mm when the last portion is less than 5 mm and less than 6 mm. , The distance d192 is shifted so as to increase by 0.1 mm every time the last portion increases by 1 mm. The bevel height vh at this time is determined by the angle 163? F (? 2 on Fig. 15A) of the front bevel machining inclined plane 163F by setting the distance d192.

When beveling the front surface of the lens, it is assumed that the intersection of the front surface of the lens and the bevel inclined surface comes to a position of the same grindstone radius (Rt) as that of the rear surface of the lens. When a bevel inclined surface is formed on the entire surface of the lens of the high curve lens, it is not preferable from the viewpoint of appearance if a bevel shoulder is provided on the front surface of the lens so that the bevel shoulder is not formed. Therefore, in the calculation of the front bevel processing data, the equation (3)

, And substituting the expression (4)

(I = 1, 2, 3, ..., N) can be obtained in the same manner as in the case of the rear surface of the lens by replacing the front bevel processing data LVi, Zmax i,

The control unit 50 controls the Y axis movement of the carriage 101 based on the data LVi for every lens rotation angle xi of the front bevel processing data and also controls the X axis movement of the carriage 101 based on the data Zmax i Respectively. As a result, a bevel slope VSf is formed on the entire surface of the lens, and even a high curve bevel can reduce the problem of bevel slimming due to interference.

As described above, the bevel setting based on the thickness of the corners of the lens LE has been described, but is not limited thereto. The presence or absence of the formation of the front bevel is divided by 3 mm in the end portion, but is not limited to 3 mm. The presence or absence of front bevel formation may be selected by an operator. In this case, the bevel apex position may be changed by the button key 512 on the simulation screen displayed on the display 5 shown in Fig.

The above-described setting of the bevel height vh of the rear surface is appropriate when it is set according to the kind of the spectacle frame. 4, the operator selects the type of the spectacle frame in a state in which the lens type FT is displayed on the screen 500 of the display 5. In this case, as shown in Fig. When the metal is selected as the material of the spectacle frame, the bevel height vh is set to 2 mm, and when the cell is selected as the material of the spectacle frame, the control unit 50 sets the bevel height vh to 3.5 mm do. Further, as shown in Fig. 8, the height of the rear side bevel can be changed by operating 541b displayed on the display 5. Fig.

As described above, by changing the bevel height of the back surface of the lens according to the input of the material of the spectacle frame, the appearance when the lens LE is sandwiched between the spectacle frames can be improved.

The high-curve bevel finishing grindstone 163 is configured such that the front bevel machining bevel 163F and the rear bevel machining bevel 163Rs are adjacent to each other, but the present invention is not limited thereto. 17, a front bevel machining inclined surface 163F is disposed at one of both ends of the grindstone group 168 and a rear bevel machining inclined surface 163Rs and a rear bevel shoulder machining inclined surface 163Rk are disposed at the other end . In the arrangement of the grindstone of Fig. 3, the vicinity of the boundary between the front bevel machining inclined plane 163F and the rear bevel machining inclined plane 163Rs can not be used for actual machining. However, by employing the configuration as shown in Fig. 17, it can be used for machining over the whole of the front bevel machining inclined surface 163F and the rear bevel machining inclined surface 163Rs.

1 is a view for explaining a processing part of the spectacle lens processing apparatus.

2 is a view for explaining a measuring unit.

3 is a view for explaining the configuration of the grindstone group.

4 is a view for explaining a control system.

5A to 5B are views for explaining the measurement of the position of the Coba of the lens.

6A to 6B are second diagrams for explaining the measurement of the position of the Coba of the lens.

7A to 7C are diagrams for explaining the lens rotation speed control.

8 is a view for explaining a simulation screen of a bevel shape.

9 is a view for explaining the positional relationship between the lens and the grindstone group.

10A to 10B are second diagrams illustrating the positional relationship between the lens and the grindstone group.

Figs. 11A to 11B are diagrams for explaining acquisition of external dimensions before lens processing. Fig.

12 is a second drawing for explaining the acquisition of the external dimensions before the lens processing.

Fig. 13 is a third drawing for explaining the acquisition of the external dimensions before lens processing.

14 is a view for explaining the formation of a bevel of the high curve lens.

15A to 15B are views for explaining a method for obtaining bevel processing data.

16A to 16B are views for explaining a front bevel.

Fig. 17 is a view for explaining another configuration of the grindstone group. Fig.

Claims (7)

In a spectacle lens processing apparatus for beveling the edge of a lens, A lens chuck shaft for holding the spectacle lens, A V-groove bevel grindstone having a V-groove for simultaneously processing a bevel inclined face on the front side of the lens and a bevel inclined face on the rear side of the lens, a front bevel grindstone for processing the bevel inclined face on the front face side of the lens and the bevel inclined face on the rear face side of the lens, A bevel processing grindstone having two types of bevel grindstones, a rear bevel grindstone, And covar position detecting means for detecting the position of the covar, which is the circumferential surface of the lens front surface and the rear surface of the lens, A mode selecting means for selecting whether the lens is in a low curve lens processing mode or a high curve lens processing mode, When the low-curve lens machining mode is selected by the mode selecting means, a predetermined arithmetic expression based on the covariance position information by the covariance position detecting means determines the position of the lens from the center of the lens on the bevel inclined surface A bevel locus for a low curve for locating a bevel vertex at a distant point is obtained to obtain low curve bevel processing data by a V-groove bevel grinding wheel, Wherein when the high-curve lens processing mode is selected by the mode selecting means, the bevel apex is located at a position shifted from the front curve or the front curve of the lens by a predetermined distance to the rear side based on the covar position information by the covar- Calculating means for obtaining a bevel locus for a high curve so as to position the bevel locus for the high curve to obtain high curve bevel processing data by a rear bevel grinding wheel, a front bevel grinding wheel and a rear bevel grinding wheel, In the low curve lens processing mode, bevel processing is performed on the edge of the lens by the V-groove bevel grinding wheel based on the low curve bevel processing data, and in the high curve lens processing mode, a rear bevel grinding wheel Or bevel processing control means for performing bevel processing by the front bevel grindstone and the rear bevel grindstone. The spectacle lens processing apparatus according to claim 1, When the high curve lens processing mode is selected and the bevel locus for the high curve is obtained such that the bevel apex is located at a position shifted to the rear side by a predetermined distance from the front curve of the lens, And a bevel locus for a high curve which changes the shift amount with respect to the lens rear surface side according to the thickness of the cornea of the lens obtained by the above method. The spectacle lens processing apparatus according to claim 1, Wherein when the high curve lens machining mode is selected, the calculation means further calculates a high curve beveling bevel position at which the bevel apex is located on the front curve of the lens when the thickness of the lens barrel obtained by the lens cooper position detecting means is less than a predetermined thickness, And a bevel locus for high curves obtained by shifting the vertex of the bevel along the curve on the front face of the lens to the backside of the lens when the thickness of the lens barrel is thicker than the predetermined thickness. The spectacle lens processing apparatus according to claim 1, Wherein an angle formed by the beveled inclined surface of the rear bevel grindstone with respect to the axial direction of the lens chuck shaft is larger than an angle formed by the rear beveled inclined surface of the V- Wherein an angle formed by the bevel machining inclined surface of the front bevel grindstone with respect to the axial direction of the lens chuck shaft is smaller than an angle formed by the front bevel machining inclined surface of the V groove bevel grindstone with respect to the axial direction of the lens chuck shaft. Processing equipment. The rear bevel grindstone of the spectacle lens processing apparatus according to claim 1, A bevel processing inclined surface on the rear side of the lens and a bevel shoulder processing inclined surface forming a bevel shoulder, Wherein an angle formed by the bevel shoulder machining inclined surface with respect to the axial direction of the lens chuck shaft is smaller than an angle formed by the bevel machining inclined surface with respect to the axial direction of the lens chuck shaft. The spectacle lens processing apparatus according to claim 1, The rear bevel grindstone has a bevel machining inclined surface on the rear side of the lens and a bevel shoulder machining inclined surface that forms a bevel shoulder. The angle formed by the bevel shoulder machining inclined surface with respect to the axial direction of the lens chuck shaft is determined by the bevel machining inclined surface, Lt; RTI ID = 0.0 > Wherein the calculation means obtains high curve bevel processing data in which the height of the bevel apex relative to the bevel shoulder when the bevel inclined plane is machined varies depending on the material of the spectacle frame input to the frame material input means Processing equipment. The spectacle lens processing apparatus according to claim 6, Wherein the calculating means obtains high curve bevel processing data in which the position of the bevel apex relative to the bevel shoulder when the material of the spectacle frame is the cell is higher than the position of the bevel apex relative to the bevel shoulder when the eyeglass frame is made of metal, Processing equipment.

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